The present invention relates generally to the field of orthodontics. More particularly, the present invention relates to orthodontic positioning appliances shaped to compensate for non-elastic deformation and related methods.
An objective of orthodontics is to move a patient's teeth to positions where function and/or aesthetics are optimized. Traditionally, appliances such as braces are applied to the patient's teeth by an orthodontist or dentist and the set of braces exerts continual force on the teeth and gradually urges them toward their intended positions. Over time and with a series of clinical visits, the orthodontist adjusts the appliances to move the teeth toward their final destination.
More recently, alternatives to conventional orthodontic treatment with traditional affixed appliances (e.g., braces) have become available. For example, systems including a series of preformed shell appliances have become commercially available from Align Technology, Inc., Santa Clara, Calif., under the trade name Invisalign® System. An Invisalign® System shell appliance can be made from thin clear plastic and have teeth receiving cavities. In use, the shell appliance is placed over the patient's teeth and is removable. Shell appliances are designed to impart positioning or repositioning forces to the patient's teeth. The imparted forces are resilient in nature and are associated with corresponding appliance elastic deformation. When used to reposition teeth, a series of individual appliances are worn by a patient to elastically reposition the patient's teeth over time. When used to position teeth, one or more identical shell appliances are worn to restrain a patient's teeth in their current arrangement.
While alternative orthodontic treatment systems using patient removable positioning appliances represent a considerable advancement in the field of orthodontics, appliance design improvements remain of interest. For example, in some cases undesirable non-elastic deformation may occur due to use of a shell appliance. Therefore, appliance design systems, as well as related systems, that address and/or compensate for such undesirable deformation would be beneficial.